Pump.



PATENTED 00T. 6, 1903.

vNo. 740,386.

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UNITED STATES patented october 6, 190e. V`

ROBERT L. BENSON, OF CHICAGO, ILLINOIS.

kPUMP.

PECIFICATION forming part of Letters Patent N0. '7443,386,v dated. October 6, 1903.

Application led August 22,1900. Serial No. 27.704. (No model.) Y

To all whom t may con/00711- Be itknown that LROBERT L.BENSON,a citizen of the United States, residing at Chicago,

in the county of Cook and State ot' Illinois,

have inventedl a certain new anduseful Improvement in Pumps, (Case No. 2,) of which the following is a full, clear, concise, and exact description, reference being had to the accompanying drawings, forming a part of this specification. p

My invention relates to pumps, and more particularly to that class of pumps in which hollow piston-rods are employed for conveying the pumped duid from the pump-barrel.

My invention comprises an improved form of valve that is very simple in construction and effective in operation and an improved arrangement of valves in the hollow pistonrod, whereby the construction of the pump is greatly simpliledand the effectiveness of its operation increased.

In practicing the first feature of my invention I preferably employ a Valve-stem that carries a valve at one end and is provided with a suitable enlargement at the other end that serves to prevent a removal of the valvestem, which is loosely fitted within the valvepassage. The valve-stem is preferably formed of wire, and the enlargementcarried thereby is preferably formed by a continuation of the wire that is bent into an eye.

The secondfeature of my invention, generally speaking, comprises a hollow piston-rod adapted to reciprocate Within a suitable pump-barrel, a piston carried by the pistonrod and snugly fitting the pump-barrel, and a valve located directly in the hollow pistonrod upon each side of the piston, the valvepassages adcrding direct communication betyveen the hollow bore of the piston-rod and the space within the pump-barrel.

Heretofore complicated valving meanshave been employed in pumps of this general type which required a great deal of space, were dicult of construction and repair, and incapable in many instances to effect their purpose.

I will explain my invention more fully by reference to the accompanying drawings, in which Figure 1 is a longitudinal sectional view of a pump constructed in accordance with my invention; and Fig. 2 an enlarged longitudinal sectional view, an intermediate portion of the pn mp structure being broken away.

Like parts are indicated by similar characters ot' reference in the views.

The pump-barrel a is constructed of any suitable metal and is provided at its upper end with a closing-cap b, the outer rim of which engages a gasket c, that may be of rubber, that is supported upon a rim d, integral with the purnpbarrel a. The cylindrical rim of the cap b has threaded engagement at the upper end of the pump-barrel, by which Vengagement the said rim is forced into firm contact with the gasket. The cap b is provided with a cylindrical elongation that constitutes a part of the stuffing-box e, through which the hollowr piston-rod fis adapted to reciprocate. The piston-rod f is preferably extension h of this enlargement being hollow `and braced thereby and having direct commnnication with the interior of the pistonrod and serving as a means ot' attachment for a duct il, that is preferably iieXible and in the form of a rubber hose. A handle 7c, that may vbe grasped by an operator, is mounted upon the upper end of thev hollow piston-rod, the screw by which the handle'` is secured to the piston-rod serving to close the upper end of the said rod. The lower end 'ot the pist-onrod is provided with a clQsure-cap Z, that prefprovided with an enlargement g, that serves. to limit its downward travel, a transverse erably has threaded engagement therewith. v A piston m is provided nearthe lower end of the piston-rod and is secured thereto by means of washers n n, that have threaded engagement with the piston-rod.. A valve o is provided above the piston, and a valve p is provided below the same, these valves opening and closing the valve-passages provided in the piston-rod, which arel adapted when the valves are in suitable position to afford direct communication between the interior of the piston-rod and the pump-barrel. I have found that Where the valves o and p are entirely disengaged they may not operate perfectly under all circumstances, as owing to the high degree ot' curvature of the pistonrod they are likely to be thrown out of advjustment with respect thereto and are not always likely to perfectly close the valve-pas- IOC) sages. I therefore mechanically unite the valves by an interposed mechanical connection that serves to maintain the valves in proper alinement with respect to each other and with respect to the inner wall of the piston-rod, this interposed mechanical connection preferably being an integral part of a loose strip of leather, the ends of which constitute the valves proper. Valves q and r are provided at the upper and lower ends of the pump-barrel and operate in a manner to be hereinafter set forth, the valve r being contained within a screw-cap s,inserted within a passage provided in the base of the pump, the passage having communication with the pump-barrel, as the drawings show. Each of the valves preferably comprises a wire stem t, which is bent into the form of an eye u upon the exterior of the pump-barrel and pistonrod, as indicated, the remaining ends of the valve-stems carrying the valves. In order that the valve structure o may not be injured by the upward movement of the piston-rod, I provide a collar e or other suitable form of stop, which by engaging the cap b serves to limit the upward travel of the piston-rod and to prevent the valve structure from coming in contact with the said cap. The stop e preferably contains a recess yw, surrounding the piston-rod, the stop thus acting as aguard to collect oil that might otherwise flow down the piston-rod and minute particles of metal or other foreign substances that. would otherwise be blown into the piston-rod and from the piston-rod blown through the duct t'. I find it important to provide this shield, especially where the pump is used for atomizing or vaporizing apparatus used in the treatment of affections of the respiratory tract, as otherwise the foreign particles might find access to the system of the patient. I am thus enabled to provide a very simple and efficient `rel beneath the piston.

pump structure whose parts are readily accessible, easily replaced and repaired.

The pump as herein described operates as follows: Assuming the piston to be traveling upwardly,the valve 7' will be opened, while the valve p will be closed, so that as the piston ascends duid is drawn into the pumpbar- Upon the reciprocal stroke of the piston the valve p will open,

while the valve r will close, so that fluid willv opened, when the piston-rod is moving upwardly.

While I have herein shown and particularly described the preferred form of my invention,

I do not wish to be limited to the precise construction illustrated; but,

Having thus described my invention, I claim as new and desire to secure by Letters Patent 1. In a pump, the combination with the pump-barrelhavingits opposite endsprovided with inlet-valves, of a piston arranged within the pump-barrel, a hollow'piston-rod closed at its inner end and carrying the piston and having apertures in the portion of the pistonrod extending on opposite sides of the piston, and a loose strap arranged within the pistonrod and having portions adapted to serve as valves for closing the said piston-rod against the outflow of tiuid, the said strap by its mounting being moved as the piston is reciprocated to bring its end portions alternately into valve-closingpositions, substantially as described.

2. In a pump, the combination with a pumpbarrel having its opposite ends provided with inlet-valves, ofa piston arranged within the pump-barrel, a hollow piston-rod carrying said piston and having apertures on opposite sides of the piston, a strap arranged within the piston-rod and having portions adapted tov serve as valves for closing said piston-'rod against the outflow of fiuid, pins connected with said strap and arranged to slide in said apertures,said pins'being provided with heads adapted to prevent their being drawn through the wall of the piston-rod, and means for closing the inner end of the piston-rod, substantially as described.

3. In a pump, the combination with the pump-barrel, of inlet-valves arranged at the opposite ends thereof, a piston arranged within the barrel, a hollow piston-rod carrying said piston and having apertures on opposite sides thereof, means for closing the end of the piston, a strap arranged within the pistonrod and having portions adapted to provide inlet-valves for the said piston-openings, pins arranged to work in said openings and connected with the valve portions of said strap, the said pins having their outer ends enlarged, and a stop arranged above the uppermost of said valves, said stop comprising a collar having its upper surface provided with arecessed portion, substantially as described.

4. The combination with a pump-barrel, of a piston adapted for reciprocation therein, the hollow piston rod carrying a piston, a valve interposed between the piston and one end of the pump-barrel, and a shield interposed between the said valve and the said end of the pump-barrel forl intercepting foreign material that would otherwise tiow into the hollow piston-rod, substantially as described.

In witness whereof I hereunto, subscribe my name this 15th day of August, A. D. 1900.

ROBERT L. BENSON.'

Witnesses:

GEORGE L. CRAGG, HARVEY L. HANSON.

Ido 

